The present invention relates to an electric lock which is unlocked electrically and more particularly to an electric lock whose electric power consumption is very small.
In the cases of conventional electric locks, a magnetic card reader reads information which is magnetically recorded on a magnetic card, as is well known in the art, and whether an electric lock is to be unlocked or not is determined by comparing the information read out of the magnetic card with reference information inherent to each room. When the electric lock is to be unlocked, an electric actuator such as an electromagnetic solenoid or a micromotor is energized in response to an electrical unlocking signal so that a dead bolt or the like is displaced in the direction in which the electric lock is unlocked or a strike on the side of a door frame which is made into engagement with the dead bolt or the like is released, whereby the electric lock is unlocked.
As described above, in the conventional electric locks, a locking member or mechanism is directly actuated by an electric actuator and naturally has inertial and the frictional resistance. Therefore, in order to assure the positive unlocking operation of the electric lock, a considerable amount of electric power must be supplied to the electric actuator. As a result, it is impossible in practice to supply electric power from a battery power supply because of rapid power consumption of a battery. Therefore power supply lines must be arranged for electric locks.
As compared with mechanical locks such as tumbler locks, it is difficult to illegally unlock an electric lock so that electric locks are highly reliable with regard to safety. Therefore, electric locks are very suitable as locks of rooms of hotels or the like where various persons visit. Another advantage of electric locks resides in the fact that when they are installed in hotels or the like, the electric locks of all guest rooms can be simultaneously unlocked from a front office of the hotel in case of an emergency such as fire or earthquake. However, as described above, the electric power consumption of conventional electric locks is relatively high so that a power supply with a high capacity, which is not necessary except in the case of an emergency, must be installed in order to simultaneously unlock all the electric locks of all guest rooms.